This invention is directed to providing enhanced adhesion of polyethylene terephthalate (PET) resin to paperboard substrates to facilitate use of lower coatweights of the resin for providing a moisture barrier.
Currently, extrusion coatweights of 28 to 32 pounds per ream of polyethylene terephthalate resin are applied to bleached board grades for dual ovenable tray applications such as in connection with frozen food containers. In addition to higher manufacturing costs, heavy coatweights result in issues with die cutting and product formability. There is therefore a need to develop processes and/or materials to be able to lower the coatweight of extruded polyethylene terephthalate film while retaining its high adhesion to paperboard to fit the end-use performance requirements.
It is an advantage of this invention to provide a primer allowing lower polyester coatweights on paperboard.
It is another advantage of the invention to provide PET coated paperboard having improved die cutting and formability characteristics.
It is still another advantage of the invention to provide a primer for improved adhesion enhancement of PET to the felt side of clay coated paperboard.
These other advantages of the invention will be apparent to one of ordinary skill in the art after reading the following description of the invention.